docs: def generate_ecc_signing_key(algorithm):
      """Returns an ECC signing key.
  
      :param algorithm: Algorithm object which determines what signature to generate
      :type algorithm: aws_encryption_sdk.identifiers.Algorithm
      :returns: Generated signing key
      :raises NotSupportedError: if signing algorithm is not supported on this platform
      """
      try:
          verify_interface(ec.EllipticCurve, algorithm.signing_algorithm_info)
          return ec.generate_private_key(curve=algorithm.signing_algorithm_info(), backend=default_backend())
      except InterfaceNotImplemented:
          raise NotSupportedError("Unsupported signing algorithm info")